RATIONALE: Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die. Radiation therapy uses high-energy x-rays to damage tumor cells. Combining chemotherapy and radiation therapy may kill more tumor cells.

PURPOSE: Phase II trial to study the effectiveness of combining temozolomide with radiation therapy in treating patients who have newly diagnosed anaplastic oligodendrogliomas or mixed anaplastic oligoastrocytomas.

OBJECTIVES:

• Determine the rate of progression in patients with newly diagnosed anaplastic oligodendrogliomas or mixed anaplastic oligoastrocytomas treated with neoadjuvant and concurrent temozolomide with radiotherapy.
• Determine the toxicity of this regimen in these patients.
• Determine the survival of patients treated with this regimen.

OUTLINE: This is a multicenter study. Patients are stratified according to response to neoadjuvant temozolomide (stable disease or partial response (PR) vs complete response (CR)).

Patients receive oral temozolomide on days 1-7 and 15-21. Treatment repeats every 28 days for up to 6 courses in the absence of disease progression or unacceptable toxicity. Patients with CR or PR receive 2 courses beyond CR or PR.

Within 6 weeks after completion of neoadjuvant temozolomide, patients with stable disease or PR undergo radiotherapy 5 days a week for 6.5 weeks. Patients also receive oral temozolomide daily for 42 days concurrently with radiotherapy.

Patients with CR after completion of neoadjuvant temozolomide undergo observation.

Patients are followed at 9 and 12 months, every 4 months for 1 year, every 6 months for 3 years, and then annually thereafter.

PROJECTED ACCRUAL: A maximum of 37 patients will be accrued for this study within 12 months.

DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed supratentorial pure or mixed anaplastic oligodendroglioma

  • Unifocal or multifocal disease
  • Prior suspected or proven low-grade glioma eligible provided biopsy reveals pure or mixed anaplastic oligodendroglioma that has not been previously treated with radiotherapy and/or chemotherapy

• No equivocal oligodendroglial element

• No tumors predominantly located in the posterior fossa (i.e., brainstem or cerebellum)

• No spinal cord tumors

• No evidence of spinal drop metastasis or spread to noncontiguous meninges

PATIENT CHARACTERISTICS:

Age:

• 18 to 65

Performance status:

• Zubrod 0-1

Life expectancy:

• More than 12 weeks

Hematopoietic:

• Absolute granulocyte count at least 1,500/mm^3
• Platelet count at least 100,000/mm^3
• Hemoglobin at least 10 g/dL

Hepatic:

• Bilirubin no greater than 2 times normal
• Aspartate aminotransferase (AST) no greater than 3 times normal
• Alkaline phosphatase no greater than 2 times normal

Renal:

• Creatinine no greater than 1.5 times normal

Other:

• No active infection
• No other medical problems that would preclude study participation
• No other malignancy within the past 3 years except carcinoma in situ of the cervix or nonmelanoma skin cancer
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• Not specified

Chemotherapy:

• See Disease Characteristics
• No prior chemotherapy for this malignancy
• No prior temozolomide

Endocrine therapy:

• Not specified

Radiotherapy:

• See Disease Characteristics
• No prior radiotherapy to the brain, head, or neck

Surgery:

• At least 14 days since prior surgery requiring general anesthesia